KB5038603 Windows 11 Insider Dev build 26120.1252 (24H2)

Hello Windows Insiders, today we are releasing Windows 11 Insider Preview Build 26120.1252 (KB5038603) to the Dev Channel. This update is delivered in a format that offers a preview of enhancements to servicing technology on Windows 11, version 24H2. To learn more, see https://aka.ms/CheckpointCumulativeUpdates.

REMINDER: Windows Insiders in the Dev Channel will now receive updates based on Windows 11, version 24H2 via an enablement package (Build 26120.xxxx). For Insiders in the Dev Channel who want to be the first to get features gradually rolled out to you, you can turn ON the toggle (shown in the image below) to get the latest updates as they are available via Settings > Windows Update. Over time, we will increase the rollouts of features to everyone with the toggle turned on. Should you keep this toggle off, new features will gradually be rolled out to your device over time once they are ready.

Turn on the toggle to get the latest updates as they are available to get new features rolled out to you.

Going forward, we will document changes in Dev Channel builds in two buckets: new features, improvements, and fixes that are being gradually rolled out for Insiders who have turned on the toggle to get the latest updates as they are available and then new features, improvements, and fixes available to everyone in the Dev Channel.

Changes and Improvements gradually being rolled out to the Dev Channel with toggle on*

[General]

We are beginning to enable again the set of new features we started to enable on 6/28 but paused on 6/30. We’re starting the enablement of these at a small percentage at first so not all Insiders in the Dev Channel with this toggle turned on will see all these features right away. And some features may show up while others might not just yet.

You can now also pin apps from the Start menu to the taskbar by dragging and dropping items directly to taskbar from the pinned section in the Start menu.

[File Explorer]

Drag-and-drop files with your mouse functionality between breadcrumbs is now available in the File Explorer Address Bar – thanks again Insiders that shared feedback about this!

[Lock screen]

We’re beginning to roll out Weather and more to your lock screen starting with this build in the Dev Channel. Stay informed and efficient with dynamic updates that bring finance, traffic, and sports to your Lock screen, alongside weather. The card design has been improved with acrylic blur, card size, spacing, and font optimizations. To turn on this feature, go to Settings > Personalization > Lock screen. To learn more, see Personalize your lock screen.

[Widgets]

[ADDED] We are also making some improvements to the Widgets button on the taskbar so that the icons on the taskbar are clearer and we are rolling out a larger set of animated icons too.

Fixes gradually being rolled out to the Dev Channel with toggle on*

[File Explorer]

Fixed an issue which could make explorer.exe crash when navigating away from Home.

[Input]

Fixed an issue where if you went through Windows Setup (OOBE), pinyin would be unexpectedly displayed twice in the list of available input methods.

[Other]

~~Fixed an underlying issue believed to be the cause of Insiders seeing error 0x80370106 when trying to launch Windows Sandbox after the latest flights.~~
Fixed an issue which was causing the preferred audio volume (under Settings > System > Sound > Volume Mixer) for Microsoft Edge to not persist across restarting the app.

Fixes for everyone in the Dev Channel

[General]

Fixed an issue causing some Insiders to see a bugcheck with error KERNEL_SECURITY_CHECK_FAILURE in recent flights.
Fixed an issue believed to be the underlying cause of some Insiders noticing stutters in some animations recently (dropping frames), particularly with Task View.

[Input]

Fixed an issue causing a cyclical input crash in the previous flight for a small number of Insiders, which impacted various input experiences.
Fixed an issue where the Input Method Editor (IME) candidate list may fail to show or showed in the wrong position.
Fixed an issue causing Insiders to see errors when attempting to use Voice Typing with certain languages such as Chinese.

[Taskbar & System Tray]

Updated the app icon flashing in the taskbar to be a bit easier to see.

[Settings]

Fixed an issue where Settings > System > Power & Battery unexpectedly had duplicate text when showing a warning about a slow charger.
Fixed an issue causing Insiders to see errors when attempting to use Voice Typing with certain languages such as Chinese.

[Other]

This update brings Country and Operator Settings Asset (COSA) profiles up to date for certain mobile operators.
Fixed the underlying issue causing some Insiders to see a Pcasvc.dll error dialog pop-up with the message “Missing entry: PcaWallpaperAppDetect” after upgrading from Windows 11, version 22H2/23H2 to a 26xxx build.

Known issues

[General]

[IMPORTANT] Windows Insiders joining the Dev Channel on PCs running Windows 11, version 24H2 Build 26100.xxxx will see “(repair version)” noted next to the latest Dev Channel build from Windows Update. This is nothing to worry about as all it means is that an in-place upgrade will happen to update your PC to the latest build in the Dev Channel.
[NEW] There’s an issue in this build where the Windows Update page in Settings is not displaying correctly for Insiders using certain languages (no text shows). If you are impacted by this, the update when the next flight goes out should still happen on its own, however you may need to wait a little bit.
[NEW] Adding additional languages or optional features may fail with error 0x800f081f.

[Task Manager]

Navigating between different pages in Task Manager may crash Task Manager.

[Windows Sandbox]

[ADDED 7/16] Windows Sandbox will fail to launch with error 0x80370106.

Reminders for Windows Insiders in the Dev Channel

Updates released to the Dev Channel are based off Windows 11, version 24H2.
Features and experiences included in these builds may never get released as we try out different concepts and get feedback. Features may change over time, be removed, or replaced and never get released beyond Windows Insiders. Some of these features and experiences could show up in future Windows releases when they’re ready.
Many features in the Dev Channel are rolled out using Control Feature Rollout technology, starting with a subset of Insiders and ramping up over time as we monitor feedback to see how they land before pushing them out to everyone in this channel.
Some features in active development we preview with Windows Insiders may not be fully localized and localization will happen over time as features are finalized. As you see issues with localization in your language, please report those issues to us via Feedback Hub.
Windows Insiders in the Dev Channel who want to be the first to get features gradually rolled out to you*, you can turn ON the toggle to get the latest updates as they are available via Settings > Windows Update. Over time, we will increase the rollouts of features to everyone with the toggle turned on. Should you keep this toggle off, new features will gradually be rolled out to your device over time once they are ready.
Because the Dev and Beta Channels represent parallel development paths from our engineers, there may be cases where features and experiences show up in the Beta Channel first.
Check out Flight Hub for a complete look at what build is in which Insider channel.
Copilot in Windows** is being rolled out gradually to Windows Insiders across our global markets. Customers in the European Economic Area will be able to download the Copilot in Windows experience as an app from the Microsoft Store.